Carburizing box



.Fan. 17, 1939. w HOFFMAN 2,144,374

CARBURI ZING BOX Filed ot. 21, 1957 2 Sheets-Sheet 1 Jan. 17, 19391 w.G. HOFFMAN CARBURIZING BOX Filed Oct. 21, .1937

2 Sheets-Sheet 2 III-n Patented Jan. 17 1939 I UNITED STATES cannu'arzmonon Walter G. Hoflnun, Chicago, 11]., aaaignor to The American BrakeShoe and Foundry Com,

a corporation of Delaware application Octobcr 21, 1987, sci-m No.110.220 11 Claims. (oi. ass-4s) The present invention relates tocarburiaing boxes for use in heat treating furnaces, this been the usualpractice tocast these boxes in one piece, and the same have frequentlybecome distorted or cracked because of the alternate heatlB ing andcooling (lining the cycle of operations, or because of the differentialheating while in the furnaces, such'diiferential heating being causedprincipally because one side of the boxes is subjected to the directheat of the furnace a. while the other side remains cooler due to beingadjacent to a cooler body, such, for example. as another box beingheated.

It is therefore an obiett of the present invention to provide a boxwherein the various eleg ments forming the same are interlocked togetherbut movable relative to one another to prevent such cracking, twisting,warping, buckling or distortion which would otherwise h take place ifthe elements were securely con- 30 nected together or the box formed asa unita y structure. Still another object of the present invention is toprovide a box wherein the various elements thereof are interlockedtogether but the joint as therebetween being so formed as to permitlongi-- tudinal movement of certain of said elements in respect to theother and to permit other relative movement of saidelements.

The present invention also contemplates the g idea of providing ajointed box permitting relative movement of the various elements whichmay, if desired, be formed with corrugations to reinforce the same. I

Still another object of the present invention is i 45 to provide a boxin which the side walls are interlocked as above mentioned. and in whichone of the open ends thereof is closed by a wall connected thereto toprovide a certain amount of clearance so that the last-named wall canmove so or expand in any direction.

The present invention-also contemplates the idea of providing a jointedbox as above described in which the closure member for one of the openends thereof is formed as a separate unit'and 35 connected thereto insuch a way as to have relative movement with respect to the jointed sideand end walls, thus eliminating cracking and warping. More inparticular. the present invention contemplates such a construction inwhich the wall serving as a closure for the open end of g the jointedbox flts into and is held in place by grooves provided in the end wallsand which is further formed with oppositely disposed marginal ribsembracing the side walls to limit the outward movement of the side wallsin case the same bow l0 outwardly from any cause.

Other objects. features, capabilities and advantages are comprehended bythe invention, as will later appear and as are inherently possessedthereby. l5

Referring to the drawings:

Figure l is a top plan view of a carburizing box made in accordance withthe present invention;

Figure 2 is a fragmentary view partly in elevation and partly incross-section taken in the 20 planes represented by lines 2-4 of Figurel ofthe drawings;

Figure 3 is a fragmentary view partly in elevation and partly incross-section taken in the planes represented by lines 3-3 of Figure 1of 25 the drawings;

Figure 4 is an enlarged fragmentary view in horizontal cross-section ofa Joint formed in the box as disclosed in Figure l of the drawings;

Figure 5 is a top plan view of a carburizing so box made in accordancewith the present inven tion and disclosing a modified form ofconstruction therefor; I

Figure 6 is a view in cross-section taken in the plane represented byline H of Figure 5 of the as drawings; and

Figure}! is a view in cross-section taken in a plane represented by line1-1 of Figure 5 of the drawings. v

Referring now more in detail to the drawings, an anillustrativeembodiment selected to disclose the present invention is shown inFigures 1 to 4 inclusive as comprising the end walls 2 and d and theside walls 6 and 8 connected together at the joints it, it, it and it toform an interior compartment it to receive the various articles to beheat treated, it Ming understood that these wall sections may be made ofchromium, nickel or other appropriateheat-resistant alloy as desired.The end walls 2 and i are of similar conan struction, the same being ofanydesired depth and width and the central portions thereof may becorrugated as shown at 20, if desired, for reinforcing p o Thesecorrugations extend toward and merge with the inwardly disposed d5portions 22 and 24, which are of'rounded contour,

and which form in part the sides of the box and terminate in the sockets28 and 28, respectively.

are incorporated in the side wall construction for.

the same purpose. This corrugated central portion merges with andterminates in the end portions 82 and 34 disposed substantiallyin thevsame plane, the same terminating to provide lugs or balls 28 and 88.

The sockets such as 28 and 28 of the end walls are formed as moreparticularly shown in Figure 4 of the drawings,fto provide theoppositely disposed walls 48 and 42 having the restricted opening 44 atthe face thereof so as to provide the interior elongated socket orrecess 48, the restricted opening 44 extending between the walls 48 and42 being of such a width as to receive the end portions such as 82 and840i the side walls and to provide clearance between said walls 82 and34 and the walls 48 and 42 to permit angular movement between the wallsof the receptacle. The' elongated sockets or recesses 48 extendthroughout'the depth of the end walls 2 and 4 and are adapted to receivethe lugs or elongated balls such as 88 and 88 formed adjacent the endsof the sidewalls 8 and 8, it being understood that these lugs orelongated balls are preferably coextensive with the side walls 8 and 8and cooperate with. the sockets throughout their entire length. Theelongated sockets are extended in a direction to provide clearance withsaid elongated lugs or balls to permit relative linear movement betweenthe sides and ends of the box.

It will therefore be clearly apparent that because, of the elongatedball and socket type of Joints formed between the end and side walls andthe clearance provided between the walls 32 and 84 and the walls 48 and42, these walls are efiectively connected together to resist pressure atany point thereon and to maintain the desired form for the box. Thesejoints also permit relative angular and linear movement between thewalls so as to prevent undesirable warping, twisting or distortion ofthe box which would otherwise take place if the same were of ing, ordiilerential heating when these boxes are in service and used in heattreating furnaces.

In order to lock the end and side walls together and to preventdisengagement of the lugs in the sockets, locking lugs such as 48 may beprovided. These locking lugs 48 are received within a suitable slot,such as 58, provided in the wall 42 of the sockets, and which slots areadapted to coincide with a slot such as 52 pro-, vided in one face ofthe lugs, such as 88 and 88, whereby relative displacement between thelugs and sockets is prevented and the relative movement of the wallslimited to movement substantially in .the direction of the dispositionof said side walls 8 and 8. These locking lugs or'keys 48 may be securedin Place in any desired manner, but preferably by welding, such as shownat 54 in Figure 4 of the drawings.

In Figures 5, 6 and 7 of the drawings is disclosed a carburizing box orreceptacle'made in accordance with the present invention but varyingsomewhat in construction from that disclosed in Figures 1 to 4 inclusiveof the drawings. 4 This carburizing box or receptacle is formed with theend walls 88 and 8.2 and the side walls 84 and 88, the same beingsomewhat similarly constructed as the corresponding walls in Figures 1to 4 inclusive of the drawings, and being connected together by theelongated ball and socket type joints 88, 18, I2 and 14, each of which,as previously described, includes va socket I8 formed at the edge of theend walls and which receives the elongated ball or lugged edge 18 of theside wall, suflicient clearance being provided in the recess of thesocket to permit a certain amount or relative movement between the sideand end walls due to contraction and expansion without causing failurein the box,, all as hereinbefore clearly described. These side and endwalls may be corrugated, if desired, for reinforcing purposesfand thewalls are interlocked together as by means of the transverse keys 88fitting in aligned slots provided in the sockets of the end walls andone of the lugs at the ends of the side walls, this key being secured inplace as by means of welding or the like.

The present embodiment of Figures 5, 6 and 7 includes an additional wall82 for closing one of the open ends of the receptacle, this wall, in theillustrative embodiment, being shown. as a bottom for the assembled sideand end walls. As

' shown, the end walls 88 and 82 are each provided with the inwardlyextending spaced flanges 84 and 88 extending from one socket to theother to provide the grooves 88 and 88, which grooves extend througheach of the sockets of the end 88 and 82 whereby the same rest upon theedge portions 84 and 88 of the wall 82 when the box is assembled andheld together by the keys 88. The ribs 88 and I88 cooperate with theside walls 84 and 88, respectively, to limit the outward movement ofsaid side walls in case the same bow outwardly from any cause.

It will be clearly understood, of course, that in assembling thereceptacle, the wall 82 is disposed within the grooves 88 and 88 at thetime the side and end walls are assembled, and that the same is held inassociation therewith by means of the keys 88 which cooperate with theelongated ball and socket type joints 88, l8, l2 and ,74 in order tohold the assembled receptacle or box together. If desired, the wall 82may be of flat construction or may be provided with lugs projecting fromthe underside to act as legs for supporting the box assembly as shown.In the illustrative embodiment of Figures 5, 6 and '7, the corrugatedportions on the walls 82 serve to support the entirebox assembly, theend walls resting upon the oppositely disposed edges of the wall throughthe flanges. 84 and the side walls resting on the edge portions 84 and88. It will be clearly understood that sufficient clearance between thewall 82 and the grooves 88 and construction and is so arranged inrespect to theother elements of the box as to permit relative movementbetween the same and the side and end walls, thus preventing crackingand warping due to expansion and contraction of the parts and whichwould be instrumental in causing box or receptacle by removing thelocking keys From the above disclosure it will be quite apparent thatthe carburizing box disclosed in the drawings is of such a constructionthat relative movement between the walls thereof may take place withoutcreating stresses in theboi: which would distort, crack or otherwisecause failure thereof when in use. The construction of the box is suchas to compensate for expansion and contraction, and is also of suchadesign that one or more of the elements thereof may be replaced withoutinconvenience and without necessitating the scrapping of the entire box.Such a construction leads to beneficial results not only from thestandpoint of serviceability, but also from the standpoint of cost perunit of material handled and heat treated and the cost of maintenance.

As an example, it will be evident from the foregoing specification thatthe term a receptacle for use in heat treating furnaces is intended toinclude all uses of a receptacle embodying the invention, involvingsubjection of the box to high temperatures in furnaces in general,whether the treatment process be termed carburizing, heat treating,annealing or normalizing, or otherwise designated. It is also to beunderstood that the invention includes boxes or containers for thepurposes stated having their confines articulated in a manner to preventthe setting up of undesirable stresses in the structure as a whole,

through means permitting flexibility on vertical axes or elongation orcontraction of one confine relative to another,.regardless of theparticular construction of articulation.

While I have herein described and upon the drawings shown illustrativeembodiments of the invention, it is to be understood that the inventionis not limited thereto but may comprehend other constructions,arrangements of parts, details and features without departing from thespirit of the invention.

I claim:

1. A receptacle for use in heat treating furnaces, comprising oppositelydisposed end and side walls forming the interior compartment of saidreceptacle, certain of said walls having an elongated socket providedadjacent an edge thereof, and certain other of said walls being providedwith a lug adjacent an edge thereof cooperating with said socket toprovide a joint whereby said walls have sumcient relative angular andlinear movement therebetween to compensate for unequal elongation of anywall with respect to another due to unequal expansion.

2. A receptacle for use in heat treating furnaces, comprising oppositelydisposed end and side walls forming the interior compartment of saidreceptacle, said walls being connected by elongated ball and socket typejoints whereby said walls have suficient relative angular and linearmovement therebetween to compensate for unequal elongation of any wallwith respect to another due to unequal expansion.

3. A receptacle for use in heat treating furnaces, comprising oppositelydisposed end and side walls forming the interior compartment of saidreceptacle, certain of said walls having a socket formed to provide arecess adjacent an edge thereof, and certain other of said walls beingprovided with a lug adjacent an edge thereof cooperating with saidsocket, said sockets being extended in directions to provide clearancewith said walls whereby said walls have sumcient relative angular andlinear movement therebetween to compensate for unequal elongation of anywall with respect to another due to unequal expansion.

4. A receptacle for use in heat treating furnaces, comprising oppositelydisposed end and side walls forming the interior compartment of saidreceptacle, said end walls being provided with sockets having recessesadjacent the edges thereof, and said side walls being formed with lugsadjacent the edges thereof and received by said sockets, said socketsbeing extended in directions to provide clearance with said wallswhereby joints are provided therebetween permitting angular and linearmovement of said luss in said recesses and relative movement of saidwalls.

, 5. A receptacle for use in heat treating furnaces, comprisingoppositely disposed end and side walls forming the interior compartmentof said receptacle, said walls being connected by elongated ball andsocket type joints whereby said walls have sumcient relative angular andlinear movement therebetween to compensate for unequal elongation of anywall with respect to another due to unequal expansion, and means forinterlocking said elongated balls in said sockets. 6. A receptacle foruse in heat treating furnaces, comprising a plurality of wall sectionsforming said receptacle, means for connecting the ends of said walls toprovide an articulated construction whereby said walls have sufiicientrelative movement therebetween to compensate for unequal elongation ofany wall with respect to another clue to unequal expansion, and a wallforclosing an open end of said receptacle, and means for connecting saidlast-named wall to said receprelative movement therebetween tocompensate for unequal elongation of any wall with respect to anotherclue to unequal expansion, a wall for closing an open end of saidreceptacle, certain of said oppositely disposed walls being providedwith a ledge disposed adjacent an edge thereof for receiving andsupporting said last-named wall and to provide {or limited relativemovement therebetween, and means for holding said assembled receptacletogether.

8. A receptacle for use in heat treating fur naces, comprisingoppositely disposed end and side walls forming the interior compartmentof said receptacle, certain of said walls having a socket providedadjacent an edge thereof, certain other of said walls being providedwith a lug adjacent an edge thereof cooperating with said socket toprovide a joint whereby said walls have suiiicient relative movementtherebetween to compensate for unequal elongation of any wall withrespect to another due to unequal expansion, a wall for closing an openend of said receptacle, means for connecting said last-named wall tosaid first-named walls, said means comprising oppositely arrangedgrooves each adapted to receive the edge of an adjacent wall and toprovide clearance whereby said last-named wall is adapted to moverelative to said first-named walls, and means associated with saidfirst-named walls for holding said assembled receptacle together.

9. A receptacle for use in heat treating furnaces, comprising oppositelydisposed end and side walls forming the intrior compartment of saidreceptacle, said walls being connected by elongated ball and socket typejoints wherein said sockets are provided with recesses extended in a onto provide clearance with said elongated balls whereby said walls havesumcient relative movement therebetween to compensate for unequalelongation of any wall with respect to another due to unequal expansion,a wall for closing an open end of said receptacle, means for connectingsaid last-named wall to said first-- named walls, said means comprisingoppositely arranged grooves each adapted to receive the edge of anadjacent wall and to provide clearance whereby said last-named wall isadapted to move relative to said first-named walls, said last-named wallhaving marginalribs embracing certain of said first-named oppositelydisposed walls. to limit the outward movement thereof, and means asso-.

ciated with said first-named walls for holding said assembled receptacletogether.

10 A receptacle for use in heat treating furnaces, comprising oppositelydisposed end and side walls forming theinterior compartment of saidreceptacle, said end walls being provided with sockets having recessesadjacent the edges thereof, said side walls being formed with lugsadjacent the edges thereof and received by said sockets, said socketsbeing extended in a direction to provide clearance with said lugswhereby joints are provided therebetween permitting movement of saidlugs in said recesses and relative movement of said walls, a wall forclosing an open end of said receptacle, said first-named end walls beingprovided with grooves adapted to receive opposite edges of saidlast-named wall and to provide clearance whereby said walls are adaptedto move relative to one another, said last-named wall having marginalribs embracing said first-named side walls to limit the outward movementthereof, and meansassociated with said first-named walls for holdingsaid assembled receptacle together.

11. A receptacle for use in heat treating furnaces, comprising aplurality of upstanding side wall sections forming said receptacle whenconnected together, and means providing an articulated joint between theadjacent side wall sections, said means having means providing forlimited relative angular and linear movement between said wall sections.

WALTER G. HOFFMAN.

